The present invention relates to a vacuum switch including a vacuum interrupter having a displaceable connection bolt, and a drive device and a lever arrangement assigned to the vacuum interrupter, for connecting the common drive device to the vacuum interrupter. The lever arrangement has a two-armed drive lever which is connected in an articulated fashion to the displaceable connection bolt. On one side of the displaceable connection bolt the drive lever is connected to the drive device and interacts on the other side of the displaceable connection bolt with a fixed counter bearing, in addition with a contact spring and a current-loop assembly, formed from a flexible strip conductor, for obtaining a force which increases the contact force of the vacuum interrupter as a function of the current.
A vacuum switch slightly similar to that described above has been disclosed by German Patent Document No. DE-B-24 50 424. The vacuum switch described in this publication is a three pole protector in which the current-loop assembly serves, in the correctly switched on state, to increase the contact force as a function of current and to enlarge the opening force during switching off in order to break apart possible fusing of the switching elements. The current-loop assembly forms an independent assembly whose spatial requirement is approximately equal to the spatial requirement of the two-armed drive lever.